Polyurethane-backed products with a polyurethane skin are well known for use as automobile dashboards. Unfortunately, the polyurethane materials will react with moisture in the air to generate CO.sub.2 which will cause the material to foam, reduce its density and generate various size voids in the polyurethane layer. The degree to which this occurs depends on humidity and in extreme cases, such as high humidity summer days, renders the process unusable. Control of this variable has previously required that costly humidity controls be installed on the spray booth air makeup units. Problems may also be encountered on extremely low humidity days in the winter, causing the material density to rise and its thickness to decrease, increasing material usage to achieve the desired thickness.
Polyurea materials, due to their intrinsic rapid reaction rates, are almost impervious to moisture variation. This is due to the fact that the polymer forming reaction is preferred over the reaction of the isocyanate with water to generate CO.sub.2. Therefore, there exists a need for a process which is insensitive to ambient moisture variation.